Epson TM-U220 Series Service Manual

3-18 Troubleshooting Rev. B
Confidential
Cannot pass one of the tests for a sensor
Cannot pass the NE (near-end) sensor test
Cannot pass the test for the RE (real end) sensor
Table 3-22 Test for the NE Sensor Fails
Probable part/probable cause Checkpoints Action to correct the problem
NE lead wire set (1096)
Check connection. Ensure cable is
plugged in. Be sure the NE lead wire set
(1096) is connected to the connectors
below.
Micro switch (1039)
Connector (CN6) on the main circuit
board unit (201)
Plug in the connector. Completed if
the test passes.
Check the continuity with a tester. Make
sure wires are not cut or shorted out. Verify
that wires are arranged correctly.
Replace the NE lead wire set.
Completed if the test passes.
Micro switch (1039)
Check micro switch (1039) operation.
Make sure the continuity changes when
you operate the switch.
Replace the near-end sensor.
Completed if the test passes.
NE detector holder (1042)
NE detector lever (1043)
Check the operation. Make sure the NE
detector lever rotates smoothly.
Replace the NE detector holder or
lever. Completed if the test passes.
Main circuit board unit (201)
Check the parts for defects.
Make sure connectors (CNC2 and CN6)
are connected.
Replace the main circuit board unit.
Completed if the test passes.
Table 3-23 Test for the RE Sensor Fails
Probable part/probable cause Checkpoints Action to correct the problem
HP board assembly (518)
Check the connection. Make sure the
cable is plugged in. Make sure the
connector on the HP board assembly
(518) is connected to connector (CN4) on
the main circuit board unit (201).
Plug in the connector. Completed if
the test passes.
Check the continuity with a tester. Make
sure wires are not cut or shorted out. Be
sure wiring is arranged correctly.
Replace the HP board assembly
(518). Completed if the test passes.
Paper end assembly (514)
Check the continuity of paper end
assembly (514) wires with a tester. Make
sure wires are not cut or shorted out. Be
sure wiring is arranged correctly.
Replace the paper end assembly.
Completed if the test passes.
Main circuit board unit (201)
Check the parts for defects.
Make sure connector (CN4) is connected.
Replace the main circuit board unit.
Completed if the test passes.

Epson TM-U220 Series Specifications

General

Print Method	9-pin, serial impact dot matrix
Autocutter	Partial cut
Weight	Approx. 2.5 kg
Paper Thickness	0.06 to 0.085 mm
Operating Temperature	5 to 45 °C
Interface	RS-232, Bi-directional parallel, USB, Ethernet
Number of Columns	42 columns
Data Buffer	4 KB
Character Set	95 Alphanumeric, 128 x 12 Graphic
Power Supply	AC adapter
Operating Humidity	10% to 80% RH (non-condensing)
Print Speed	4.7 lines per second (at 40 columns, 16 dpi)
Paper Width	76 mm / 69.5 mm / 57.5 mm ± 0.5 mm
Copy Capability	Original + 2 copies